Stuffed Meatloaf

Name: Stuffed Meatloaf
Ingredients: 1 small onion, grated; 3 garlic cloves, minced; 1/4 cup chopped fresh Italian parsley leaves; 2 large eggs; 1/4 cup ketchup; 1 teaspoon salt; 3/4 teaspoon ground black pepper; 2/3 cup dried bread crumbs; 1 cup grated Parmesan; 8 ounces ground beef; 8 ounces ground pork; 8 ounces ground veal; 2 cups (packed) Ciabatta Stuffing with Chestnuts and Pancetta, recipe follows, or your favorite stuffing; 1/2 cup marinara sauce; 3/4 cup grated provolone; 6 tablespoons (3/4 stick) butter; 8 ounces pancetta, cut into 1/4-inch dice; 2 large onions, finely chopped; 2 carrots, peeled and finely chopped; 3 celery stalks, finely chopped; 2 tablespoons chopped fresh rosemary leaves; 3 garlic cloves, chopped; 2 (7.4-ounce) jars roasted peeled whole chestnuts, coarsely broken; 1 pound day-old ciabatta bread, cut into 3/4-inch cubes; 2/3 cup freshly grated Parmesan; 1 cup (or more) canned low-salt chicken broth; Salt and freshly ground black pepper; 2 large eggs, beaten to blend